The long-term objective of this project is to develop a tissue engineered cardiac graft (TECG) for use in the surgical repair of congenital and acquired lesions of the heart. The end-point objective of the research proposed herein is to develop a structurally well-organized and electromechanically functional TECG eliciting demonstrable mechanical benefits in an in vivo rat model of myocardial infarction (Ml). This end-point objective will be approached by first quantifying the efficacy of protein-modified, poly(glycerol sebacate) (PGS) elastomeric scaffolds exhibiting cell-orienting 3-D open pore structures (cellular guidance motifs; CGM) to promote cardiomyocyte (CM) adhesion, survival, and alignment. Secondly, the efficacy of in vitro biaxial mechanical stimulation in promoting the organization of electromechanically functional TECG suitable for implantation will be assessed. The specific aims are: 1. Microfabricate elastomeric scaffolds with cellular guidance motifs (CGM). 2. Quantify CM adhesion, survival, and alignment on protein-modified CGM-PGS scaffolds. 3. Quantify TECG electromechanical function in response to in vitro biaxial stretch. 4. In vivo studies of TECG in a rodent model of myocardial infarction (Ml). [unreadable] [unreadable] [unreadable]